KERATOCONUS

DIVYA.N INTERN. OPTO

DEFINITION

• Usually Bilateral,Non inflammatory progressive ectasia of cornea resulting in irregular myopic astigmatism

• Common in Hot and Dry climate

• Family history is usually negative from patients but survey shows evidence of genetics

CAUSES

• Exact cause: UNKNOWN!• Extensive eye rubbing• Inheritance• Improper fitting/ extended CL wear• Certain allergic disorders • Overexposure to UV rays

• Keratoconus (from Greek: kerato- horn, cornea; and konos cone) is a degenerative disorder of the eye in which structural changes within the corneacause it to thin and change to a more conical shape than its normal gradual curve.

DIAGNOSIS• History taking

• Chief complaints

• Symptoms and signs

• Topometric reports

SYMPTOMS

• Blurred or distorted vision• Frequent change of glasses• Ghosting/monocular diplopia• Haloes around light• Glaring problem mainly night

SIGNSEARLY LATE

Scissoring retinoscopic reflex

Irregular astigmatism

Distorted keratometric mires

Cone formation

Corneal thinning

Advanced cone formation

Non uniform red reflex in ophthalmoscopy

Munsons sign

Slit lamp findings:Vogts lineFleishers ringScarring in corneal epithelium

SCISSORING REFLEX

Distorted keratometric mires

Munsons sign

Vogt’s Line

Flieshers ring

TREATMENTTREATMENT

COLLAGEN CROSS LINKING• It is a method for stopping progression of KC• Involves a one-time application of riboflavin

solution(Vitamin drop) to the eye that is activated by illumination with UV-A light for approximately 30 minutes.

• The riboflavin causes new bonds to form across adjacent collagen strands in the stromal layer of the cornea, which recovers and preserves some of the cornea's mechanical strength.

• The corneal epithelial layer is generally removed to increase penetration of the riboflavin into the stroma.

C3R

LENSES• Glasses or soft contact lenses:Early keratoconus can be treated with

glasses or soft contact lenses to correct blurry or distorted vision. But because the condition is progressive, most people find they frequently need to change the prescription of their lenses as their corneas' shape changes.

• Rigid gas permeable contact lenses: Hard contact lenses are often the next step in treating progressing keratoconus. Rigid lenses may feel uncomfortable at first, but they will feel better later mainly with vision

• Hybrid lenses:For people who can't tolerate hard contact lenses, these contacts have a rigid center with a softer ring around the outside for increased comfort

• Piggyback: RGP on soft CL.• Customized contact lenses :These rigid gas permeable lenses are

custom created for each individual based on topographical measurements of cornea: ROSE K lens

• Scleral contact lenses These lenses are useful for irregular cornea changes, because they rest on sclera and vault over the cornea, instead of resting on the cornea like traditional lenses.

INTACS

• Surgical procedure for removing the corneal stroma down to Descemet’s membrane

• Host corneal endothelium is retained, and anterior corneal tissue is replaced with normal thickness donor tissue.

• As the host endothelium is retained there is no risk of rejection, and steroids have to be given only for a short duration of time

Deep Anterior Lamellar Keratoplasty (DALK)

REMEMBER!

• Make patient clearly understand about KC and its progressiveness

• Objective refraction may not work due to scissoring,make a good subjective refraction.

• While giving Glass explain patient that change may occur in power frequently.

• Followup very important• Depending on stage of KC advice proper

treatment

THANK YOU&

GOOD NIGHT!